Reorganize desktop roles: extract common bootstrap and host-specific layers

- Add profile_desktop_common with shared desktop bootstrap (emptty, PAM,
  dotfiles, templates, GPG, Maildir, Flatpak, st, external tools)
- Add profile_desktop_host with host-specific tasks (NVIDIA/PRIME on nymph)
- Reduce profile_desktop_i3 to i3/X11-only tasks
- Create profile_desktop_hyprland for Hyprland Wayland session
- Add dual-session support (i3 + Hyprland) on nymph with session choice
- Create shared Hyprland/Waybar dotfiles under dotfiles/desktop/
- Fix Waybar: bottom position, no persistent workspaces, sort by number
- Rename host_dotfiles to host_i3_dotfiles for clarity
- Make emptty restart manual by default to avoid session drops

dotfiles/desktop/.local/bin/lock-session

@@ -0,0 +1,23 @@
+#!/bin/sh
+
+set -eu
+
+case "${XDG_CURRENT_DESKTOP:-}" in
+  *Hyprland*|*hyprland*)
+    exec hyprlock
+    ;;
+  *i3*|*I3*)
+    exec "$HOME/.config/i3/scripts/lockscreen"
+    ;;
+esac
+
+if command -v hyprlock >/dev/null 2>&1; then
+  exec hyprlock
+fi
+
+if [ -x "$HOME/.config/i3/scripts/lockscreen" ]; then
+  exec "$HOME/.config/i3/scripts/lockscreen"
+fi
+
+printf '%s\n' 'No supported lock command found.' >&2
+exit 1

dotfiles/desktop/.local/bin/powermenu

@@ -0,0 +1,42 @@
+#!/bin/sh
+
+set -eu
+
+choice="$(printf 'Shutdown\nReboot\nLogout\nLock\nSuspend' \
+| rofi -dmenu \
+  -i \
+  -p 'Power' \
+  -theme ~/.config/rofi/config.rasi \
+  -theme-str 'window { width: 20%; location: center; anchor: center; } listview { columns: 1; spacing: 6px; }')"
+
+[ -n "$choice" ] || exit 0
+
+case "$choice" in
+  Lock)
+    "$HOME/.local/bin/lock-session"
+    ;;
+  Logout)
+    case "${XDG_CURRENT_DESKTOP:-}" in
+      *Hyprland*|*hyprland*)
+        hyprctl dispatch exit
+        ;;
+      *i3*|*I3*)
+        i3-msg exit
+        ;;
+      *)
+        printf '%s\n' 'Unsupported desktop session for logout.' >&2
+        exit 1
+        ;;
+    esac
+    ;;
+  Suspend)
+    "$HOME/.local/bin/lock-session" || true
+    loginctl suspend
+    ;;
+  Reboot)
+    loginctl reboot
+    ;;
+  Shutdown)
+    loginctl poweroff
+    ;;
+esac

dotfiles/desktop/.local/bin/screenshot-wayland

@@ -0,0 +1,33 @@
+#!/bin/sh
+
+set -eu
+
+mode=${1:-full}
+target_dir="$HOME/Pictures/Screenshots"
+target_file="$target_dir/$(date +%Y-%m-%d-%H%M%S).png"
+
+mkdir -p "$target_dir"
+
+case "$mode" in
+  full)
+    grim "$target_file"
+    ;;
+  region)
+    grim -g "$(slurp)" "$target_file"
+    ;;
+  output)
+    grim -g "$(slurp -o)" "$target_file"
+    ;;
+  *)
+    printf 'Usage: %s [full|region|output]\n' "$0" >&2
+    exit 1
+    ;;
+esac
+
+if command -v wl-copy >/dev/null 2>&1; then
+  wl-copy < "$target_file"
+fi
+
+if command -v notify-send >/dev/null 2>&1; then
+  notify-send "Screenshot saved" "$target_file"
+fi

dotfiles/desktop/.local/bin/setup-gtk-theme

@@ -0,0 +1,38 @@
+#!/bin/sh
+
+THEME="Yaru-blue-dark"
+ICONS="Yaru-blue-dark"
+CURSOR="Yaru"
+FONT_UI="Liberation Sans 10"
+
+mkdir -p "$HOME/.config/gtk-3.0"
+mkdir -p "$HOME/.config/gtk-4.0"
+
+cat > "$HOME/.config/gtk-3.0/settings.ini" <<EOF
+[Settings]
+gtk-theme-name=$THEME
+gtk-icon-theme-name=$ICONS
+gtk-cursor-theme-name=$CURSOR
+gtk-font-name=$FONT_UI
+gtk-application-prefer-dark-theme=1
+gtk-xft-antialias=1
+gtk-xft-hinting=1
+gtk-xft-hintstyle=hintslight
+gtk-xft-rgba=rgb
+EOF
+
+cat > "$HOME/.config/gtk-4.0/settings.ini" <<EOF
+[Settings]
+gtk-theme-name=$THEME
+gtk-icon-theme-name=$ICONS
+gtk-cursor-theme-name=$CURSOR
+gtk-font-name=$FONT_UI
+gtk-application-prefer-dark-theme=1
+EOF
+
+if command -v gsettings >/dev/null 2>&1; then
+  gsettings set org.gnome.desktop.interface gtk-theme "$THEME" >/dev/null 2>&1 || true
+  gsettings set org.gnome.desktop.interface icon-theme "$ICONS" >/dev/null 2>&1 || true
+  gsettings set org.gnome.desktop.interface cursor-theme "$CURSOR" >/dev/null 2>&1 || true
+  gsettings set org.gnome.desktop.interface color-scheme prefer-dark >/dev/null 2>&1 || true
+fi

dotfiles/desktop/.local/bin/start-hyprland-session

@@ -0,0 +1,22 @@
+#!/bin/sh
+
+[ $# -gt 0 ] || set -- Hyprland
+
+[ -r /etc/profile ] && . /etc/profile
+[ -r "$HOME/.profile" ] && . "$HOME/.profile"
+
+set -e
+
+session_name=${1##*/}
+
+export XDG_CURRENT_DESKTOP="$session_name"
+export XDG_SESSION_DESKTOP="$session_name"
+export XDG_SESSION_TYPE=wayland
+
+exec dbus-run-session sh -eu -c '
+  umask 077
+  printf "%s\n" "$DBUS_SESSION_BUS_ADDRESS" > "$HOME/.dbus-session-bus-address"
+  eval "$(ssh-agent -s)" >/dev/null
+  gpgconf --launch gpg-agent
+  exec "$@"
+' sh "$@"